Regarding such type of techniques, JP-A No. 2000-254131 cited here below describes a ligation apparatus that sucks the hemorrhoid with a negative pressure through a forceps hole of an endoscope inserted into a tubular body, and then detaches, with a fluid injected from a syringe or the like, an O-ring attached in advance to a front end portion of the tubular body, to thereby ligate the hemorrhoid.
Also, JP-A No. 2004-167257 and U.S. Pat. No. 5,741,273 cited below describe a ligation apparatus that sucks the hemorrhoid utilizing a housing with an O-ring attached to a front end portion thereof and a plunger, and then detaches the O-ring by pushing a thumb pusher provided outside the housing toward the front end portion, to thereby ligate the hemorrhoid.
Those ligation apparatuses are employed in combination with a funnel-shaped anoscope. Accordingly, the operator such as a doctor uses a hand to insert a small-diameter tip portion of the anoscope into the anus of the patient, and the other hand to operate the ligation apparatus.    [Patented document 1] JP-A No. 2000-254131    [Patented document 2] JP-A No. 2004-167257    [Patented document 3] U.S. Pat. No. 5,741,273